Very wide band tactical vehicular antenna system

Abstract

An antenna system includes a first antenna portion operating over a first range of frequencies, a second antenna portion operating over a second range of frequencies and an antenna matching network that receives a transmission line which includes a single conductor and a coaxial cable. The coaxial cable has an inner conductor insulated from an outer conductor, wherein the first antenna portion is fed by the single conductor and the outer conductor, and the second antenna portion is fed by the inner conductor.

What is claimed is: 
     
       1. An antenna system comprising:
 a first antenna portion operating over a first range of frequencies; 
 a second antenna portion operating over a second range of frequencies; 
 an antenna matching network comprising:
 a housing having a ground portion and an output portion; 
 a housing insulator separating said ground portion from said output portion; 
 an unbalanced-unbalanced matching transformer comprising a ferrite core maintained in said housing; and 
 a ground lead; and 
 a transmission line comprising a single conductor and a coaxial cable, said coaxial cable having an inner conductor insulated from an outer conductor, wherein said first antenna portion is fed by said single conductor and said outer conductor, and said second antenna portion is fed by said inner conductor, 
 
 wherein said ground lead and said outer conductor are connected to said ground portion, wherein said single conductor is connected to said outer conductor of said coaxial cable, wherein said ground lead is connected to said outer conductor of said coaxial cable, wherein said coaxial cable and said ground lead are wrapped around said ferrite core, wherein said outer conductor is connected to said output portion, and wherein said inner conductor passes through said output portion. 
 
     
     
       2. The antenna system according to  claim 1 , further comprising:
 a tank circuit maintained by said first antenna portion to drop out selected frequencies emanating from said first antenna portion. 
 
     
     
       3. The antenna system according to  claim 1 , wherein said first antenna portion comprises at least one network such that as the frequency of operation changes, the effective impedance of the network changes to limit the antenna currents that exist above the network. 
     
     
       4. The antenna system according to  claim 3 , wherein said first antenna portion further comprises a plurality of radially extending arms at an end opposite said housing. 
     
     
       5. The antenna system according to  claim 1 , wherein said second antenna portion comprises at least one biconic antenna fed by said inner conductor. 
     
     
       6. The antenna system according to  claim 1 , wherein said first range of frequencies is 30 to 512 MHZ. 
     
     
       7. The antenna system according to  claim 1 , wherein said second range of frequencies is 500 to 2500 MHZ. 
     
     
       8. A method, comprising:
 providing a housing having a ground portion and an output portion separated by a housing insulator; 
 maintaining an antenna matching network having a ground lead and an unbalanced-unbalanced matching transformer having a ferrite core in said housing; 
 connecting a transmission line to said antenna matching network, said transmission line comprising a single conductor and a coaxial cable, said coaxial cable having an inner conductor insulated from an outer conductor; 
 connecting said single conductor to said outer conductor; 
 connecting said ground lead in said antenna matching network to said ground portion and said outer conductor; 
 wrapping said ground lead and said outer conductor around said ferrite core of said unbalanced-unbalanced matching transformer; 
 connecting said outer conductor to said output portion; 
 passing said inner conductor through said output portion; 
 feeding a first antenna portion by said single conductor and said outer conductor, said first antenna portion operating over a first range of frequencies; and 
 feeding a second antenna portion by said inner conductor, said second antenna portion operating over a second range of frequencies. 
 
     
     
       9. The method of  claim 8 , further comprising;
 maintaining a tank circuit by said first antenna portion to drop out selected frequencies emanating from said first antenna portion. 
 
     
     
       10. The method of  claim 8 , further comprising:
 using at least one network of said first antenna portion such that as the frequency of operation changes, the effective impedance of the network changes to limit the antenna currents that exist above the network. 
 
     
     
       11. The method of  claim 10 , wherein said first antenna portion further comprises a plurality of radially extending arms at an end opposite said housing. 
     
     
       12. The method of  claim 11 , further comprising:
 feeding at least one biconic antenna of said second antenna portion by said inner conductor. 
 
     
     
       13. An antenna system, comprising:
 a transmission line comprising a coaxial cable having an outer conductor that surrounds an insulator which surrounds an inner conductor, and a single conductor, wherein said single conductor is connected to said outer conductor; 
 a housing receiving said transmission line wherein said housing comprises
 a ground portion; 
 an output portion; and 
 a housing insulator separating said ground portion from said output portion, wherein a ground lead and said outer conductor are connected to said ground portion and wherein said outer conductor is connected to said output portion and said inner conductor passes through said output portion; 
 
 an antenna matching network maintained in said housing, said network having a Guanella unbalanced-unbalanced matching transformer comprising a ferrite core with said coaxial cable and connected single conductor wrapped around said ferrite core to form transformer windings; 
 a first antenna portion connected to said antenna matching network, wherein said first antenna portion is fed by said Guanella unbalanced-unbalanced matching transformer with said outer conductor and said single conductor; and 
 a second antenna portion extending from said first antenna portion, wherein said inner conductor passes through said first antenna portion to feed said second antenna portion. 
 
     
     
       14. The antenna system according to  claim 13 , further comprising:
 a tank circuit maintained by said first antenna portion to drop out selected frequencies emanating from said first antenna portion. 
 
     
     
       15. The antenna system according to  claim 13 , wherein said first antenna portion comprises at least one network such that as the frequency of operation changes, the effective impedance of the network changes to limit the antenna currents that exist above the network. 
     
     
       16. The antenna system according to  claim 13 , wherein said second antenna portion comprises at least one biconic antenna fed by said inner conductor. 
     
     
       17. The antenna system according to  claim 13 , wherein said outer conductor and said connected single conductor carries a VHF/UHF signal and said inner conductor carries an L-Band signal that is effectively hidden from the operation of said VHF/UHF signal. 
     
     
       18. The antenna system according to  claim 17 , wherein said outer conductor acts as a barrier to keep said L-Band signal in said coaxial cable. 
     
     
       19. The antenna system according to  claim 13 , wherein said ground lead is wrapped a selected number of times around said ferrite core.